Boyle also directed the 1996 hit movie, a black comedy which follows a group of heroin addicts in a deprived area of Edinburgh in the late 1980s.

A 45-second clip using footage from the original film was shared by the Sony Pictures UK Twitter account to mark T2's first day of shooting on Monday.

However, photographs have already emerged of Bremner in character as Daniel "Spud" Murphy during pre-production in Edinburgh last week.

Trainspotting was based on author Irvine Welsh's novel by the same name.

The long-awaited film will likely be loosely based on Welsh's 2002 sequel to Trainspotting, titled Porno.

Carlyle, who will return to the part of "psycho" Begbie, has said that the script for the new film is "absolutely fantastic" and stronger than the first film.

The actor joined Welsh at The Usher Hall in Edinburgh in March to mark 20 years since the release of the original movie, where he said that filming will take place " pretty much 50-50" between Edinburgh and Glasgow.

He said: "I'm basing this on nothing other than the fact that the production office is on Bathgate. There's a clue there.

"What I will say is that all the characters are exactly where you would want them to be.

"The strength of this new script is the fact that the narrative is a bit stronger than it was in the original.

"In the first one, when you think about it, it's hard to remember what they did other than get together, the drug deal at the end, and then it's over."

The actor said that fans will get a chance to find out how everyone's lives have gone since they were last on screen.

"This has maybe got a wee bit more to it in terms of what they've been up to through these years," he said.

"You learn a lot about Renton, Sick Boy and indeed Begbie and where their heads are.

"I think it's an absolutely fantastic script. John Hodge has done a wonderful job, as he did with the original.

"Fingers crossed people will take it on board and they will enjoy it."

McGregor said he does not have any nerves about returning to the part of Renton.

Speaking to the Press Association ahead of the release of his new movie Our Kind Of Traitor, he said: "It's such an amazing script, penned by John Hodge who wrote the original Trainspotting script, so there's a real excitement about it.

"Like every movie you do, you have things to think about leading up to them. There is a nervousness about it, but I'm not nervous because it's a sequel to Trainspotting."

McGregor and Boyle also worked together on 1994's Shallow Grave and 1997's A Life Less Ordinary, and the actor welcomed a chance to reunite with the director on a film project.

He said: "I'm very excited. I sort of regret we spent so long not working together. I think that's a shame."